Self-propelled machine for cleaning external surfaces of pipelines

ABSTRACT

A self-propelled machine for cleaning external surfaces of pipelines in which the rotor encompassing the pipeline carries cleaning tools rotating together with the rotor and about their own axes parallel to the axis of rotation of the rotor, the tools being kinematically connected with the common drive of the machine through the drive of the rotor and, in addition, having a self-contained kinematic coupling with this drive adapted for changing the speed of rotation of the cleaning tools about their axes at a constant speed of the rotor.

United States Patent [191 Salukvadze et a1.

[ Mar. 19, 1974 SELF-PROPELLED MACHINE FOR CLEANING EXTERNAL SURFACES OFPIPELINES [76] Inventors: Viktor Samsonovich Salukvadze, 5

Parkovaya, 42. kv. 53; Igor Filippovich Koshman, ulitsa Bratskaya, 23,korpus l. kv. 176, both of Moscow; Leonid Borisovich Doktorov, ulitsaKraskovsky obryv, l1, Moskovskaya oblast, all of U.S.S.R.

[22] Filed: Mar. 22, 1972 [21] Appl. No.: 236,813

[52] US. Cl. 15/88, l5/104.04 [51] B08b 9/02 [58] Field of Search 15/88,104.04; 118/72 [56] References Cited UNITED STATES PATENTS 2.307.4491/1943 Carpmail 15/88 2.427.129 9/1947 Fields 1 15/88 2.631.315 3/1953Hauser.... l5/104.04 2.641.008 6/1953 Smith 15/88 Primary ExaminerEdwardL. Roberts Attorney, Agent. or Firm-Holman & Stern [57] ABSTRACT Aself-propelled machine for cleaning external surfaces of pipelines inwhich the rotor encompassing the pipeline carries cleaning toolsrotating together with the rotor and about their own axes parallel tothe axis of rotation of the rotor, the tools being kinematicallyconnected with the common drive of the machine through the drive of therotor and, in addition. having .a self-contained kinematic coupling withthis drive adapted for changing the speed of rotation of the cleaningtools about their axes at a constant speed of the rotor.

3 Claims, 2 Drawing Figures PATENTED MAR I 9 I974 saw 1 [1P2 4 PATENTEUMR 1 9 I974 3L797L0e0 SHEEI 2 OF 2 SELF-PROPELLED MACHINE FOR CLEANINGEXTERNAL SURFACES OF PIPELINES BACKGROUND OF THE INVENTION The presentinvention relates to devices for cleaning pipeline surfaces and, moreparticularly the invention relates to self-propelled machines forcleaning the external surface of a pipeline.

The present invention can be used most effectively for cleaning theexternal surface of a pipeline having a diameter greater than 700 mm, sothat further application onto this surface of an insulating coating canbe effected, particularly in winter when the pipeline is covered withice, frozen snow and dirt. The proposed machine can also be used forcleaning pipelines before applying thin-film insulating coatingsrequiring highquality preparation of the surface.

Known in the art are self-propelled machines for cleaning the externalsurface of a pipeline which comprise a rotor mounted on a frame andencompassing the pipeline, the rotor carrying cleaning tools rotatingtherewith and about the axes of their shafts parallel to the axis ofrotation of the rotor, each-shaft being kinematically connected with thecommon drive of the machine through a rotor rotating drive, a cardanjoint, and a sprocket engaging a central cogwheel mounted on the framecoaxially to the rotor. (of. USSR Authors Certificates No. 118095 andNo. 127118).

In these known self-propelled machines the central cogwheel isstationary. In the process of operation of these machines the rotorrotates with the cleaning tools and the latter simultaneously rotateabout the axes of I their shafts, each shaft being connected through acardan joint with the sprocket performing a planetary motion about thecentral cogwheel.

As the circumferentialspeed of the rotor and, the rotational speed ofthe sprockets are constant, the circumferential speed of the cleaningtools is also constant. In this connection, the cleaning tools in theseknown machines can only be made as cylindrical brushes.

It is known that the quality of cleaning the surface of a pipeline bymeans of these known machines is characterized by a number of runs orpassages of the cleaning toolsthrough each point of the surface beingcleaned, i.e., by the overlap factor K determined as follows wherein V,is the circumferential speed of the rotor rotating about the pipeline;

V is the circumferential speed of the working tools rotating about theiraxes;

6B is thetotal width of all the tools along the line of contact with thepipeline;

D is the diameter of the pipeline;

V is the speed of linear motion of the machine along the pipeline.

The higher the overlap factor, the better (in the general case) thequality of cleaning of the pipeline surface. However, in the knownmachines the overlap factor can be increased only at the expense ofreducing the linear speed V of the machine which is associated with anundesirable drop in the efficiency of the machine. As stated above, therotor speed V, and the dependent speed V of the cleaning tools remainconstant. In this case the circumferential speed of the rotor cannot beincreased without inevitable deterioration of the operation of themachine due to drastically increasing inertia loads.

The total circumferential speed of the rotor and the tools V, V, is theperipheral speed of cleaning and, in the final analysis, determines thequality of the cleaned surface of a pipeline provided by the givenmachine at constant efficiency thereof.

The quality cleaning of pipelines from rust and scale, particularly inthe presence of ice, frozen snow and earth, etc. on their surface cannotbe provided with the use of the known machines without increasing theperipheral speed of cleaning and the overlap factor, whilesimultaneously preserving the adequate efficiency of the machine.

Furthermore, it is well known that thin-film insulating coatings, forexample epoxy-coal, polyethylene and so on, require complete removal orthe corrosion products from the cleaned surface of a pipeline andpredetermined roughness of this surface. These factors are of decisiveimportance for adhesive resistance of the coating and its life. Theexperience has shown that the known machines are not suitable forcleaning external surfaces of pipelines for the purpose of applyingcoatings thereto.

SUMMARY OF THE INVENTION An object of the present invention is toprovide a selfpropelled machine for cleaning the external surface of apipeline having the capability of controlling the peripheral speed ofleaning at a constant circumferential speed of the rotor.

Another important object of the invention is to provide such a machinethat ensures high-quality cleaning of a pipeline for the purpose ofapplying thereon various insulating coatings regardless of the conditionof this surface prior to the cleaning, whereby the efficiency of themachine is not reduced.

These and other objects are attained by providing a self-propelledmachine in which a rotor mounted on a frame and encompassing thepipeline carries cleaning tools rotating together with the rotor andabout the axes of their shafts parallel to the axis of rotation of therotor and kinematically connected to the general drive of the machinethrough the rotor drive, a cardan joint and a sprocket engaged to acentral cogwheel mounted on the frame coaxially to said rotor. Accordingto the invention, the central cogwheel in mounted on the frame with apossibility of rotation and has a selfcontained kinematic coupling withthe general drive of the machine adapted for changing the rotationalspeed of this wheel, thereby changing the rotational speed of thecleaning tools about their axes at a constant speed of the rotor.

The self-contained kinematic coupling of the central cogwheel with thecommon drive of the machine made in the form of an engine with a powertake-off reduc tion gear is preferably effected through a chain drivewhose driven sprocket is rigidly secured on this cogwheel, while thedriving sprocket is mounted on the output shaft of a gear box whoseinput shaft is connected through a clutch to one of the output shafts ofsaid reduction gear.

Due to such an arrangement, the proposed selfcontained machine providescontrol of the peripheral speed of cleaning at a constant rotational:speed of the rotor thereby providing for high-quality cleaning of thesurface of a pipeline for the purpose of applying thereto variousinsulating coatings regardless of the condition of this surface beforethe cleaning, whereby the efficiency of the machine is not reduced.

Furthermore, this machine permits the use of more effective andlong-life cleaning tools compared to the known cylindrical brushes.

The proposed machine is preferably provided with cleaning tools made inthe form of rotary cutting tools with radially disposed lengths of wirewhose one ends are connected to one another, the lateral surfaces ofthese lengths being pressed to one another in the immediate vicinity tothese ends, and whose opposed, free ends adjoin the common cutting faceof the tool in the form of a surface of revolution, in which case theratio of the summary area of the face planes of the free ends to thetotal area of the cutting surface of the tool is 0.2-0.9.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be betterunderstood from the following detailed description of one particularembodiment of the invention with reference to the accompanying drawings,in which:

FIG. 1 is a functional diagram of the self-propelled machine forcleaning the surfaces of pipelines according to the invention;

FIG. 2 is schematic diagram of mutual disposition of the centralcogwheel, sprocket and cleaning tool (a front view, partly in section).

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT The self-propelledmachine for cleaning external surfaces of pipelines according to theinstant invention comprises a rotor 2 (FIG. I) mounted on a frame 1 andencompassing the pipeline. The rotor 2 carries cleaning tools 3 mountedon their shafts 4 rotating together with the rotor 2 and about theiraxes parallel to the axis of rotation of the rotor coinciding with thegeometrical axis of the pipeline 5. The shafts 4 of the cleaning toolsare kinematically connected to the common drive of the machinecomprising an engine 6 and a power take-off reduction gear 7. Thiskinematic coupling is effected through the drive of the rotor 2, acardan joint 8 (FIG. 2) and a sprocket 9 engaging a central cogwheel 10mounted on the frame 1 coaxially to the rotor 2.

The central cogwheel 10, according to the invention, is rotatablymounted on the frame 1 and has an independent kinematic coupling withthe common drive of the machine for changing the rotational speed ofthis wheel.

According to the invention, the independent kinematic coupling of thecentral cogwheel 10 with the common drive of the machine is effectedthrough a chain drive having a driven sprocket 11 (FIG. '1) rigidlysecured to this cogwheel and a driving sprocket 12 mounted on the outputshaft 13 of a gear box. A whose input shaft 14 through a clutch 15 isconnected to one of the output shafts of the reduction gear 7. I

In the embodiment under consideration the central cogwheel 10 consistsof two coaxially disposed drums rigidly interconnected through pins 16,between which drums there are disposed chain links 17 engaging thesprockets 9 and having a pitch equal to that of these sprockets.

Each chain link 17 (FIG. 2) has a wear-resistant bushing 18 on an axle19 rigidly secured in the drums against axial displacements.

The driven sprocket 11 is a gear rim mounted about the outer diameter ofone drumv (left-hand) of the wheel 10. The other drum (right-hand) ofthe cogwheel 10 in mounted on the frame 1 by means of supporting rollers20 (FIG. 1).

The rotor 2 is made in the form of two tyres 21 and 22 interconnectedthrough a ring 23 and secured in supporting rollers 24 and 25 mounted onthe frame 1.

The drive for rotation of the rotor 2 consists of a chain drive having adriving sprocket 26 connected with the output shaft of the reductiongear 7 and a driven sprocket 27 disposed between the tyres 21 and 22 andrigidly secured to the ring 23. The tyres 22 and 1 21 have apertures forpassing the shafts 4 of the tools 3 and the shafts 28 of the sprockets9. Thc shafts 4 and 28 are connected through the cardan joints 8 passingthrough the corresponding apertures made in the driven sprocket 27 ofthe drive for rotation of the'rotor 2.

Each shaft 4 with the tool 3 has an independent operating arrangement 29to provide for elastic contact of the tool with the worked surface ofthe pipeline 5 by means of any known method suitable for this purpose.The frame 1 is equipped with two carriages 30 and 31 performingtranslatory motion along the external surface of the pipeline 5 underthe action of the common drive of the machine. The kinematic coupling ofthe carriages 30 and 31 with the common drive of the machine is effectedthrough a clutch32, a gear box B, tranmission shafts 33 and 34, a systemof chain drives 35, 36 and 37, and worm reduction gears 38 and 39. Adiesel engine is used as the engine 6.

The proposed self-propelled machine operates as follows.

The engine 6 is started. In this case the shafts of the power take-offreduction gear 7 are rotated, and the torque is transmitted to the rotor2 of the machine and to the carriages 30 and 31 for longitudinal(relative to the pipeline 5) movement of the machine.

The rotor 2 is rotated by one of the output shafts of the reducer 7through the driving sprocket 25 and the driven sprocket 27 rigidlysecured to the ring 23 which, in turn, is secured to the tyres 21 and 22rotating in the supporting rollers 24 and 25 which rotate only abouttheir axes.

The shafts 4 and 28 connected through cardan joints and carrying thecleaning tools 3 and the sprockets 9 rotate together with the rotor 2about the geometrical axis 00 of the pipeline. In this case thesprockets 9 perform planetary motion about the central cogwheel 10 androtate the cleaning tools 3 about their own axes. Thus, there isobtained one constant speed of rotation of the cleaning tools abouttheir axes at a constant speed of the rotor: therefore, a constantcleaning speed (or rate) is provided.

The cleaning speed should be understood as the sum of the speed ofrotation of the tools about the axis 0-0 of the pipeline 5 created bythe rotor 2 and the speed of rotation of the cleaning tools 3 abouttheir axes.

The required cleaning speeds are provided by operating the gear box Awhose input shaft 14 through a clutch 15 is connected with the powertake-off reduction gear 7, while the output shaft 13 of the chain driveincluding the sprockets 1 1 and 12 is connected with the cogwheel 10. Inthis case the kinematic coupling of the motor 6 with the cogwheel l0 andthe rotor 2 is effected so as to provide for their mutually oppositerotation. In this case the rotational speed of each of the cleaningtools 3 about its axis will be added to the speed developed by therotation of the rotor, thus providing for optimum rate of cleaning ofthe pipeline most expedient under the specific conditions.

It is known and previously stated that the cleaning speed determines thequality of the surface being cleaned at a constant linear speed of themachine; the higher the cleaning speed, the greater number of passagesthrough each point of the pipeline performs the tool; thereforeiit ispossible to completely remove all the contaminations from the surface ofthe pipeline. By changing the rotational speed of the tool, the cleaningspeed is changed correspondingly.

The maximum cleaning speeds are required when the pipeline surface iscovered with ice, frozen ground and snow. An increased cleaning speed isalso required when preparing the pipeline surface for thin-filminsulating coatings to create microgeometry (roughness) of the treatedsurface and to completely remove the rust and scale from this surface.

Sometimes, when the pipeline surface is in good condition for example inthe case of only thin mill scale on this surface or when no stringentrequirements are imposed thereon, it is expedient to reduce the cleaningspeed, in which case the gear box A is set to a required speed, and thecogwheel 10 is rotated in the direction of the rotor, thus reducing thespeed of rotation of the tools 3 about their axes.

Low cleaning speeds make it possible to reduce the power consumption ofthe engine and to increase its life.

After selecting the rated cleaning speed and adjusting the arrangement29 for creating a required elastic contact of the tools 3 with thepipeline surface, the gear box B connected through the clutch 32 withthe reduction gear 7 is operated at a specified speed. In this case thetorque is transmitted to the carriages 30 and 31 mounted on the frameand effecting the longitudinal displacement of the machine along thepipeline. To prevent the proposed machine from overturning, it isprovided with a supporting wheel (not shown) the construction of whichis similar to that of the wheels employed in the known machines of thistype. This wheel is connected to the frame 1 of the machine throughsuitable links and is capable of running on the ground.

Since the speed of rotation of the cleaning tools about their axes canbe controlled at a constant speed of the rotor, the cleaning tools ofthe proposed machine can be made in the form of rotary cutting toolswith radially disposed wire lengths with interconnected ends on oneside, the lateral faces of these lengths being pressed to one another inthe immediate vicinity -to these ends, while the opposite, free endsadjoin the common cutting face of the tool in the form of a surface ofrevolution. in which case the ratio of the summary area of the faceplanes of the free ends to the total area of the cutting surface of thetool is O.2-0.9.

The use of such tools in the proposed machine widens the technologicalfacilities of the machine and considerably improves its operationalcharacteristics.

We claim:

1. A self-propelled machine for cleaning external surfaces of pipelineshaving a common drive and comprising: a frame means; carriages mountedon said frame means and kinematically coupled with said common drive soas to move said carriages along the external surfaces of a pipeline tobe cleaned; a rotor rotatably surrounding said pipeline and carryingrotatable cleaning tools operatively associated therewith,said rotorbeing mounted on said frame means and provided with an independent drivemeans for transmitting a driving torque from said common drive of themachine, said cleaning tools having their axes of rotation parallel tothe axis of rotation of said rotor; means for providing an elasticcontact between said cleaning tools and said external surface of saidpipeline, said means being mounted on said rotor adjacent said tools; acentral cogwheel rotatably mounted on said frame means coaxially withsaid rotor to rotate relative thereto; sprockets of said machine havingtheir axes parallel to the rotational axis of said rotor, said sprocketsbeing mounted on said rotor so as to operatively engage said cogwheel; acardan joint for providing kinematic connection of each of saidsprockets with a corresponding one of said cleaning tools through saidindependent rotor drive means so that during rotation of said rotor andsaid cogwheel said sprockets and said cleaning tools rotate around theirown axes at identical rotational speeds, said central cogwheel havingmeans for independent kinematic coupling thereof with said common driveof the machine for changing the speed of said cogwheel relative to therotational speed of said rotor so that the rotational speed of saidcleaning tools and said sprockets about their axes changes while therotational speed of said rotor remains constant.

2. A machine as claimed in claim 1, wherein said means for independentkinematic coupling of said central cogwheel with the common drive of themachine is effected through a chain drive having a driven and a drivingsprocket and wherein said common drive comprises an engine with apower-take-off reduction gear having at least one output shaft, saiddriven sprocket of said chain drive being rigidly secured on saidcentral cogwheel, and said driving sprocket being secured to the outputshaft of a gear box'whose input shaft is connected through a clutch toone of said output shafts of said reduction gear. I

3. A machine as claimed in claim 1, in which the cleaning tools are madein the form of rotary cutting tools having radially arranged lengths ofwire some ends of which are connected to one another while the otheropposite ends remain free, the lateral surfaces of said lengths beingpressed against one another in the immediate vicinity of said ends,while the opposite free ends of said wire lengths adjoin the commoncutting face of the tool to form a surface of revolution, so that theratio of the sum of the area of the face planes of the free ends to thetotal area of the cutting face of the tool is equal to 0.2-0.9.

1. A self-propelled machine for cleaning external surfaces of pipelineshaving a common drive and comprising: a frame means; carriages mountedon said frame means and kinematically coupled with said common drive soas to move said carriages along the external surfaces of a pipeline tobe cleaned; a rotor rotatably surrounding said pipeline and carryingrotatable cleaning tools operatively associated therewith,said rotorbeing mounted on said frame means and provided with an independent drivemeans for transmitting a driving torque from said common drive of themachine, said cleaning tools having their axes of rotation parallel tothe axis of rotation of said rotor; means for providing an elasticcontact between said cleaning tools and said external surface of saidpipeline, said means being mounted on said rotor adjacent said tools; acentral cogwheel rotatably mounted on said frame means coaxially withsaid rotor to rotate relative thereto; sprockets of said machine havingtheir axes parallel to the rotational axis of said rotor, said sprocketsbeing mounted on said rotor so as to operatively engage said cogwheel; acardan joint for providing kinematic connection of each of saidsprockets with a corresponding one of said cleaning tools through saidindependent rotor drive means so that during rotation of said rotor andsaid cogwheel said sprockets and said cleaning tools rotate around theirown axes at identical rotational speeds, said central cogwheel havingmeans for independent kinematic coupling thereof with said common driveof the machine for changing the speed of said cogwheel relative to therotational speed of said rotor so that the rotational speed of saidcleaning tools and said sprockets about their axes changes while therotational speed of said rotor remains constant.
 2. A machine as claimedin claim 1, wherein said means for independent kinematic coupling ofsaid central cogwheel with the common drive of the machine is effectedthrough a chain drive having a driven and a driving sprocket and whereinsaid common drive comprises an engine with a power-take-off reductiongear having at least one output shaft, said driven sprocket of saidchain drive being rigidly secured on said central cogwheel, and saiddriving sprocket being secured to the output shaft of a gear box whoseinput shaft is connected through a clutch to one oF said output shaftsof said reduction gear.
 3. A machine as claimed in claim 1, in which thecleaning tools are made in the form of rotary cutting tools havingradially arranged lengths of wire some ends of which are connected toone another while the other opposite ends remain free, the lateralsurfaces of said lengths being pressed against one another in theimmediate vicinity of said ends, while the opposite free ends of saidwire lengths adjoin the common cutting face of the tool to form asurface of revolution, so that the ratio of the sum of the area of theface planes of the free ends to the total area of the cutting face ofthe tool is equal to 0.2-0.9.